Wellhead control



April 6, 1937. l B; YQUNG 2,075,878 Y WELLHEAD CONTROL Fil'ed Sept. 7,1935 zo 37 l16 I4 All5oYouNer- I5 F751, famM/f Patented Apr. 6, 1937UNITED STATES WELLHEAD CONTROL Bob Young, Henderson, Tex., assignor toGranville A. Humason, Houston, Tex.

Application September 7, 1933, Serial No. 688,440

6 Claims.

The invention relates to an improvement in well head or drilling controlassemblies to be used in preventing blowout of the wells during thedrilling operation.

In the drilling of wells it is usual to provide surface casing and Wellhead thereon in order to support the various apparatus which are to beused during the drilling and flowing of the well. 'I'he drill bit anddrill stem are passed downward- 10 ly through this casing and casinghead, and caused to rotate in performing the drilling operation. Inevent the drill penetrates a gas pocket or high pressure formation. itis not unusual for the pressure encountered to overbalance the column ofdrilling iiuid which is in the well, and to blow out not only thedrilling fluid but in most instances the drillbit. Various devices havebeen conceived with a view of closing the well head as quickly aspossible when a heavy pressure is encountered. These devicesincludeblowout preventers, tubing retractors, and similar constructions.All of these, however, require the manipulation of separate andindependent devices in order to close the well head against the escapeof fluid. The present invention has therefore been devised in order toincorporate a closure lmember in the drill stem so that the well headmay be closed by merely raising the drill stem to the proper elevation.

It is one of the objects of the invention to provide a well head closurewhich constitutes an enlarged portion on the drill stem in combinationwith a restricted arrangement in the casing head so that when theseparts are at the same elevation the well head will be closed.

Another object of the invention is to provide a closure membe for wellheads which is incor. porated in the drill stem.

Another object of the invention is to provide a casing head having arestricted area which is adapted to cooperate with a closure member onthe drill stem.

A still further object of the invention is to provide a device forinstantly closing the well head in event an excessive pressure isencountered.

It is also an object of the invention to provide a method for closingthe Well bore by merely raising the drill stem to the proper elevationso that it will be caused to completely close oi the well 5o head.

Other and further objects of the invention will be readily understoodwhen the following description is considered in connection with theaccompanying drawing wherein:

55 Fig. 1 is a vertical sectional view of a well head (Cl. Z55- 1)equipped with the invention, and showing the drill stem in position toclose the well head.

Fig. 2 is a diagrammatic view showing the general arrangement andassembly of the drilling apparatus with the present inventionincorporated therein, and illustrating the parts in drilling position.

Fig. 2 shows the general arrangementv of the drilling apparatus whichembodies the derrick 2, the hoisting apparatus and traveling block 3,and the rotary swivel 4. The swivel serves to support the drill stem 5and the drill bit as well as the grief stem or kelly joint 6.

It will be understood that during the drilling operation the rotary 8 iscaused to turn, and the kelly joint 6 being of a non-circularconguration, is gripped by the rotary 8 and caused to turn. 'Thisturning, of course,l is transmitted to the drill stem 5 and the drillbit 9 to perform the drilling operation. In order that the bit maypenetrate the formation, the hoisting apparatus 3 is gradually loweredas the drilling proceeds, so that the kelly joint 6 slides through therotary 8.

In order that the cuttings may be washed away from the drill bit and thewalls of the well bore maintained, a drilling fluid is circulatedthrough the hose III and swivel 4 and discharged from the opening I I inthe drill bit. This drilling uid flows upwardly through the well bore I2and the casing I3 and is discharged from the outlet I4 into the slushpit where it is again picked up and cir.- culated through the well. Allof the apparatus so far described is standard construction, and wellknown in the drilling operation.

The upper end of the casing usually has mounted thereon some type ofcasing head which has an opening therein'of suflicient diameter topermit the passage of the drill bit 9. One of the parts of the presentinvention constitutes an improved form of casing head which isillustrated lgenerally at I6. This casing head is best seen in enlargedsection in Fig. 1 and embodies a base I1 which is attached to the pipeI8 which is in turn attached to the casing I3. The discharge or outletI4 is lshown as being carried by the pipe I8. Obviously this pipe I4will have suitable valves thereon so that the escape of iiuid from theoutlet may be cut off if desired.

The casing head I6 is of special construction in that it has an internalbore 20 which is shown as cylindrical and of sufficient length toadequately accommodate the closure member 2 I, which is shown as being aconnection or coupling between the drill stem 5 and the kelly joint 6.The upper end ofthe casing head I6 has the usual form of tapered bowl 23in order to receive the slips to support the drill stem if desired, orto support the additional tubing hangers or other constructions duringthe operation of the well.

The closure member 2| forms an essential part of the invention incombination with the casing head I6, because the closure member is ofsuch a diameter as to quite closely t within the cylindrical bore 20 ofthe casing head. The closure member comprises a head 25 connected to apacking mandrel 26, which is in turn connected to the drill stem. Anexpansible packing gland or seal 28 is shown as carried by the mandrel26 and clamped in position by the head 25. 'I'his packing may be of anydesired type, but an improved form of lip packing has been illustratedwherein the inner lip 30 is so formed as to be inserted in the recess 3|in the packing mandrel and the outer or sealing lip 32 is ofsuchdiameter that a recess 33 is formed to receive the fluid and causeexpansion of the lip 32. It should be noted that the lower end of thelip 32 extends outwardly beyond the shoulder of the packing mandrel sothat the fluid may enter the recess 33. The upper end of the packing isshown as having an inwardly turned shoulder 34 which is clamped againstthe upper end of the mandrel 26 by the head 25. From the foregoingconstruction it will be apparent that when the closing member is movedto the elevation of the bore 20 in the casing head, that the casing headwill be closed against the flow of fluid around the outside of the drillstem.

The head 25 is provided with a shoulder 36 which is arranged to abutagainst the stop pins 31 which are carried by the casing head. Two ofthese stop pins have been shown as being projected into the bore 28 sothatv any pressure accumulating in the well cannot cause the drill pipeand closure member to be ejected from the well.

These stop pins 31 are shown as being operated by means of a pressureplunger 38 which is mounted on the derrick floor 39. The conduits orpipes 40 connect the plunger 38 with the stop pins 31, and theseconduits are filled with hydraulic liquid. Pressure on the plunger 38exerts a balancedpressure on the two stop pins 31 and causes them tomove inwardly against the resistance of the springs 4|. Any desired typeof mechanical arrangement can be provided to accomplish the movement ofthese stop pins.

`The operation of the' device is as follows: 'I'he drill bit and desirednumber of sections of drill pipe are lowered into the well bore untilthe drill bit approaches the bottom of the bore where the drillingoperation is to occur. e closure member 2| is then connected to theupper section of drill pipe and the kelly joint 6 connected to theclosure member. The bit is then lowered on to the formation and thedrilling operation proceeds. It is preferable that the closure member 2|be located slightly below the bore 20 at the beginning of thedrillingoperation so that there will be no wear due to rotation on thepacking 28. It is to be understood that the kelly joint 6 is ofconsiderable length as seen in Fig. 2, and

- permits the drilling of a considerable distance.

When the kelly joint has been lowered to its full length, the apparatusis thenraised and the kelly joint and closure member as a unit aredisconnected from the upper end of the drill stem. The next section ofdrill stem is interposed in the string and the closure member and thekelly joint again connected and the drilling is resumed. Fig. 2 showsthe closure member 2| at an elevation considerably below the bore 20 inthe casing head I6.

In event excessive pressure is encountered and the driller is of theopinion that a blowout is imminent, or it is desired to close the top ofthe well, he merely operates the hoisting apparatus 3 to raise the kellyjoint and the drill bit upwardly in the well bore until the closuremember 2| arrives at the elevation of the restricted bore 20. The stoppins 31 can be moved inwardly and then if the well pressure issufficient it will raise the iluid in the Well and cause expansion ofthe lip 32 to form a complete seal in the casing head. The valve on theoutlet I4 may then be closed and this will serve to completely cut oithe escape of fluid from the well, except through the drill stem. Theescape through the drill stem may be properly controlled by a backpressure valve or the pressure overcome by the operation of thecirculating pumps.

In some formations the drill bit encounters a gas pocket and beforedrilling can proceed the gas pressure must be reduced. The usualpractice is to suspend the drill pipe and rotate it while thecirculating pumps are operated. The flushing fluid passing out throughthe drill bit and up the well bore carries some gas with it so that thepressure in the formation is reduced. 'Ihe present equipment is idealfor these operations because the well head can be closed around thekelly.

The particular advantage of the present invention resides in the factthat casing heads can be closed almost instantly by merely raising theclosure member 2| to the elevation of the restricted bore 20. This canbe accomplished very stem, drill bit swivel, and hoisting apparatus to lbe lowered in the well.

On many occasions it is necessary to raise and lower the drill stem andthis is the principal duty of the driller to have constant control ofthe hoisting apparatus at all times. He can, therefore, very quicklyraise theclosure member to the proper elevation and, by merely movingthe plu'nger 38, will have the closure member stopped at the desiredelevation to close the casing head.

It is contemplated that any size pipe may be connected to either end ofthe sealing assembly so that the well head may be closed as describedregardless of the size of pipe in the ywell. This is of advantage overthe closure heads now used which generally require -a change in the sizeof the rams with every change in size of the pipe being used.

The invention contemplates broadly a method of closing the well head bymerely raising the drill n stem during the drilling operation, and doesnot require the actuation of blowout preventers or" from the derrickfloor to limit the upward movement of the closure member in said casinghead.

2. The combination of a casing head, aexible closure member on the drillstem adapted to cooperate with the casing head to closev the well, a

l head to restrain said member against flowing under pressure, and ameans to limit the upward movement of said head in the casing head, saidmeans including radially movable hydraulically operated stop pins in thecasing head.

3. The combination with a casing head having a restricted openingtherethrough of a drill stem in said opening, said stem being made up ofpipe sections and a kelly joint, a connection for the lower end of thekelly to the pipe comprising a mandrel, a lip packing thereon, a flangeconning the inner lip, a head above said mandrel,- a shoulder thereon tosupport said packing against upward movement, and means movable intosaid opening to obstruct the upward movement of said head whereby anautomatic seal is obtained by raising said packing into said opening. l4. A drilling control head comprising a casing, a casing head thereon, aworking barrel carried by said head, a sealing assembly forming a partof the drill stem Iand disposed in said working barrel and adapted toform a seal with said barrel during the drilling operation, and meansalso on said casing head to hold said sealing assembly against removaldue to pressure in the well.

- 5. A drilling head the upper end of which comprises a working barrel,an outlet from said head below said barrel so that the circulationretums may ilow therefrom, a sealing assembly carried by the drill stemand adapted to seal in said working barrel during the drillingoperation, and means to lock said assembly against upward movement outof said barrel.

6. A drilling head the upper end of which comprises a working barrel, anoutlet from said head below said barrel so that the circulation returnsmay iiow therefrom, a sealing assembly carried by the drill stem andadapted to seal in said working' barrel during the drilling operation,and means on the top of said working barrel to latch said sealingassembly against upward movement.

BOB YOUNG.

